Data on transient atmospheric events (TAEs) were obtained from the Vernov satellite and are presented in this paper. The data are considered in conjunction with previous data obtained by the Universitetsky-Tatiana-1 and Universitetsky-Tatiana-2 satellites. The larger volume of stored scientific data in the Vernov mission and its advanced ultraviolet (UV) and red–infrared (R–IR) radiation detector (DUV) measurements allowed improved TAE-distribution data to be obtained over a wide range of photon numbers. The difference between features of luminous transients and “dim” transients, measured by the Universitetsky-Tatiana-2 satellite, is confirmed by Vernov’s data. There are also interesting dim UV events with no R–IR radiation. Such events are expected to be deep in the atmosphere at the level of thunderstorm clouds. They might be radiated by electric discharges of less power than lightning; in fact, at the preliminary stage of lightning. The observation of repeating dim TAEs in various time intervals, starting from tens of milliseconds and up to minutes, indicates that thunderstorm electric activity is much more variable than pure lightning strikes.

DOI: 10.1175/JAMC-D-16-0309.1